There are Four Methods that conducted on the laboratories in order to detect the presence of microorganisms. There are Rodac Method, Swab Method, Rinse Method, and lastly Open Dish Method and it will be discussed in detail below. 2.1.1 Rodac Method
The purpose of this Standard Operating Procedure is to describe a program that will adequately measure the efficacy of disinfection of Rooms and equipment in each laboratory, RODAC plates can detect the presence or absence of live microorganisms (Longrée and Armbruster 1996). This Method is used to monitor the contamination level of personnel gowns and Personal Protective Equipment (PPE) before or during manufacturing production. The advantages of the RODAC method are that it may be prepared and stored for weeks prior to use (Harrigan 1986). Additional advantages of the RODAC method include relatively low cost, consistent and precise recovery, effective use by personnel without extensive training, and the elimination of laboratory manipulation after sampling (Marriott and Gravani 2006). On the other hand, the disadvantages of this method are the spreading of the colonies and applicable to only limited to low levels of surface contaminants. 2.1.2 Swab Method
The Swab method is among the most Reproducible Methods used to determine the population of microorganisms present on equipment or food products (Marriott and Gravani 2006). It may be used to assess the amount of contamination from the air, water, surfaces, facilities and food products. By using this technique the equipment surfaces, facilities and food products which to be analyzed are swabbed. The swab are diluted in a dilutant such as peptone water or phosphate buffer, according to the anticipated amount of contamination and subsequently applied to a growth medium containing agar in a sterile, covered plate (David, Richard and R. 2004). There are many advantages to the cotton swab method. These include the ease with which any health care provider can procure the necessary items: a CTA or culturette transport medium (Longrée and Armbruster 1996). In addition, the method requires little expertise, with minimal training time required, and very little time required to actually perform the procedure. On the other hand, Disadvantages of the swab method are that sampling and technique can affect the results and that the method requires manipulation to culture the sample. Swabs are designed for hard-to-reach places, and can fit easily into equipment recesses, nooks, and crevices (Tamime 2008). After collection of the sample, it is recommended that a standard membrane filtration of the rinse solution be conducted.
2.1.3 Rinse Method
The Rinse Method use elution of contamination by rinsing to permit a microbial assay of the resultant suspension (Forsythe 2008). A sterile fluid is manually or mechanically agitated over an entire surface. The rinse fluid then diluted and subsequently plated, this method are more precise compared to the swab method, because a larger surface area can be tested (David, Richard and R. 2004). While the disadvantages is that it requires time and labor to prepare solutions and media, dilute samples, pour plate samples, and count colony-forming units on the plates. 2.1.4 Open Dish Method
The principle behind this method is that the bacteria carrying particles are allowed to settle onto the medium for a given period of time and incubated at the required temperature. A count of colonies formed shows the number of settled bacteria containing particles (David, Richard and R. 2004). In this method petri dishes containing an agar medium of known surface area are selected so that the agar surface is dry without any moisture. Choice of the medium depends upon the kind of microorganisms to be enumerated. For an overall count of pathogenic, commensal and saprophytic bacteria in air blood agar can be used (Longrée and Armbruster 1996). For detecting a particular pathogen which may be...